DP can record straight to compressed Theora video I think. Will look awful though. reQuiem has incredibly easy video capture (haven't tested it on Windows myself). Just make sure VSync is off and it will be only limited by your harddisk speed. Here is a slightly out of date but hopefully working beta:
http://chunk.io/f/d0bf59d08b5c4d8692ad30df8b7e9bb6Just record a demo, then "capturedemo demoname" and it will write an uncompressed AVI. Yes, those get big. Just compress them later on. If you are on Linux, just use ffmpeg+x264: "ffmpeg -i movie.avi -acodec libmp3lame -ab 192k -vcodec libx264 -preset slow -crf 20 movie.mkv"
It also has a builtin spawn command so you could easily populate the map
